Magnetically operated door latch



Dec. 18, 1962 1-. E. KIRK MAGNETICALLY OPERATED noon LATCH 2 Sheets-Sheet 1 Filed April 12, 1960 IN VENTOR; flames (5' 167% ATTQQNEY Dec. 18, 1962 K I 3,069,193

MAGNETICALLY OPERATED DOOR LATCH Filed April 12, 1960 2 Sheets-Sheet 2 JZ INVENTOR.

.7 4 BY 77501220. (EX/17% ATTORNE Y United States Patent Ofiice 3,069,193 MAGNETICALLY OPERATED DOOR LATCH Thomas E. Kirk, Anderson, Ind., assignor to General Motors Corporation, Detroit, Mich a corporation of Delaware Filed Apr. 12, 1960, Ser. No. 21,750 Claims. (Cl. 292--144) This invention relates to a door latch, and more particularly to a magnetically operated door latch.

One feature of the invention is that it provides a bolt which is movable between latched and unlatched positions, being biased toward latched position, and a magnet on the door operator for moving the bolt from latched to unlatched position against the force of the spring.

Another feature of the invention is that the bolt mounts a first magnet and a door operator mounts a second magnet Which is movable from an inoperable position remote from the first magnet to an operable position wherein a pole of the second magnet is adjacent a like pole of the first magnet where the repulsive force of the magnetic field existing between the magnets overcomes the force of the spring which biases the bolt and retracts the bolt.

A further feature of the invention is that it provides a door latch having inside and outside operators, lever means interconnecting the operators and a magnet mounted on the lever means for movement into operable position upon actuation of either of the operators.

Other features and advantages of the invention will be apparent from the following specification and drawings, in which:

FIGURE 1 is a fragmentary side elevational view of an automobile incorporating the improved magnetically operated latch;

FIGURE 2 is an enlarged fragmentary horizontal section taken along the line 22 of FIGURE 1, showing the parts as they are located when the bolt is in projected position;

FIGURE 3 is a view similar to FIGURE 2, but showing the parts as they are located when the bolt is in retracted position; and

FIGURE 4 is a section taken along the line 4-4 of FIGURE 2 and showing the position of the parts when in locked position.

Referring now more particularly to the drawings, an automobile designated generally as has a door 12 which is hinged on the body in conventional manner at the front edge of the door and which is latched to the body at the rear edge of the door. As shown in FIGURES 2, 3 and 4, the latch comprises a bolt 14 which is slidably mounted in a bolt housing 16. The bolt housing is secured by screws 18 to the jamb face 20 of the door 12. A spring 22 surrounds the bolt 14 and seats against a collar 14a on the bolt and the base of the housing 16 to bias. the bolt toward the projected or latched position shown in FIG- URE 2.

When the bolt is in latched position and the door is closed, the nose of the bolt enters a latching recess in a striker 24 which is secured by screws 26 to the jamb face portion 27 of the body which face portion defines the rear edge of the door opening. When in the latched position shown in FIGURE 2, the door is held against swinging in an opening (clockwise) direction. The bolt, which preferably is formed of non-magnetic material has mounted thereon a non-magnetic bracket 28 which projects in a direction axial of the bolt from the end of the bolt opposite the latching nose. This bracket mounts a permanent magnet 30,-there being a recess 32 between the magnet 30 and the end of the bolt. If desired, the bolt itself can be a magnet having its end opposite the bolt nose forming a pole similar in polarity to the adjacent pole of the magnet 30.

3,069,193 Patented Dec. 18, 1962 An inside push button operator 34 is slidably mounted in a casing 36 which is secured to the inner panel of the door and a push rod 38 projects into the door from the push button and is pivotally connected to one end of a lever 40 which is pivotally mounted intermediate its ends at 42 on a bracket 44 projecting into the door from the outer panel thereof. A coil spring 46 in the casing 36 biases the push button 34 toward the inoperative position shown in FIGURE 2.

An outside push button door operator 50 is slidably mounted in a gripping handle 52 which is secured by bolts '53 to the outer panel of the door 12. The push button 50 has a push rod 54 which is pivotally connected at 56 to an intermediate point on a lever 58, the forward end of which is pivotally mounted at 60 on a bracket 62 which extends into the door from the jamb face 20 thereof. A coil spring 64 biases the push button 50 toward the inoperative position shown in FIGURE 2. The other end of the lever 58 is pivotally connected by means of a pin and slot arrangement 66 to the end of the lever 40 so that when either the inside push button 34 or the outside push button 50 is depressed, the lever '40 will swing in a counterclockwise direction (FIGURES 2 and 3) from the inoperative position of FIGURE 2 to the operative position of FIGURE 3. A second magnet 68 is secured by screws 70 to the lever 40 at such a location on the lever that the magnet 68 will swing into the recess 32 when either the inside push button 34 or the outside push button 50 is depressed.

The magnets 36 and 68 are so arranged that like poles are adjacent each other when the magnet 68 is swung up into the recess 32 so that the repulsive force of the magnetic field existing between the magnets overcomes the force of the bolt-biasing spring 22 and causes the bolt to move from the latched or projected position of FIGURE 2 to the unlatched or retracted position of FIGURE 3. The combined force exerted by the relatively light push button biasing springs 46 and 64 is substantially less than the force exerted by the bolt-biasing spring 22 so that the manual force required to unlatch the door is substantially less than the force which would be required to overcome the spring 22 by direct manual operation. When the push buttons 34 and 50 are released they are returned to their inoperative position by the springs 46 and 64 so that the magnet 68 swings back to the position of FIGURE 2. With the parts in this position the force of the bolt biasing spring 22 overcomes any repulsive force which may exist between the magnets 30 and 68 when in the position of FIGURE 2 and the bolt is projected to its latched position by the bolt-biasing spring 22.

Locking means are provided for blocking movement of the latch operating means to prevent the magnet 68 from being swung from its inoperable position of FIGURE 2 to its operable position of FIGURE 3. The inside locking means comprises a garnish molding button 72 which projects out of the garnish molding panel 74 on the inside of the automobile door 12. The garnish molding button 72 is connected to a locking rod 76 which is connected to an overcenter spring 78 to hold the garnish molding button in a raised or unlocked position or, selectively, in a depressed or locked position as shown best in FIGURE 4. When the garnish molding button is depressed, the lower end of the rod 76 projects through an opening 80 in the lever 58 so that the lever arangement is blocked against swinging movement whenever the inside push button 34 or the outside push button 50 is attempted to be depressed. The door may be unlocked from the inside merely by lifting up on the garnish molding button to raise the end of the locking rod 76 up out of the opening 80 in the lever '58.

Locking may be accomplished from the outside through a conventional key cylinder 82 which is mounted on the outer panel of the door 12 and which carries an operating pawl 84 having a flange 86 which is received in the space between two spaced collars 88 and 90 on the locking rod. Turning a proper key in the key cylinder in one direction will move the pawl 84 upwardly to raise the locking rod 76 to its unlocked position and turning the key in the opposite direction will lower the pawl 84 to move the locking rod 76 downwardly to the locked position shown in FIGURE 4.

While I have shown and described one embodiment of my invention, it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention, as set forth in the appended claims.

I claim:

1. A door latch of the character described, including: a bolt mounted for slidable movement between projected and retracted positions; a single first magnet mounted on said bolt; spring means biasing said bolt toward projected position; movable latch operating means including an actuating member and a carrier lever connected thereto; and a second magnet mounted on said carrier lever, said second magnet being bodily movable along a curved path upon operation of said latch operating means from an inoperable position remote from said first magnet to an operable position adjacent said first magnet where the magnetic field existing between the magnets overcomes the force of said spring means and retracts the bolt.

2. A door latch of the character described, including: a bolt mounted for movement between projected and retracted positions; a first magnet mounted on said bolt; spring means biasing said bolt toward a projected position; an inside latch operator movable between inoperative and operative positions; an outside latch operator movable between inoperative and operative positions; lever means interconnecting said inside and outside operators; and a second magnet mounted on said lever means, said second magnet being movable upon operation of either of said operators from an inoperable position remote from said first magnet to an operable position adjacent said first magnet where the magnetic field existing between the magnets overcomes the force of said spring means and retracts the bolt.

3. A door latch of the character described, including: a bolt mounted for movement between projected and retracted positions; a first magnet mounted on said bolt; spring means biasing said bolt toward projected position; an inside latch operator movable between inoperative and operative positions; an outside latch operator movable between inoperative and operative positions; lever means interconnecting said inside and outside operators; spring means biasing said inside and outside operators toward inoperative positions; and a second magnet mounted on said lever means, said second magnet being movable upon operation of either of said operators from an inoperative position remote from said first magnet to an operable position wherein a pole of said second magnet is adjacent a like pole of said first magnet where the repulsive force of the magnetic field existing between the magnets overcomes force of the spring means which biases the bolt and retracts the bolt.

4. Apparatus of the character claimed in claim 3, wherein the spring means biasing the latch operators exert less force than the spring means biasing the bolt.

5. A door latch of the character described, including: a non-magnetic bolt mounted for slidable movement between projected and retracted positions; a spring biasing said bolt toward projected position; an inside push button latch operator movable between inoperative and operative positions; an outside push button latch operator movable between inoperative and operative positions; spring means biasing said inside and outside operators toward inoperative position, said spring means exerting less force than the spring which biases the bolt; lever means interconnecting said inside and outside push button operators; a second magnet mounted on said lever means, said second magnet being movable upon operation of either of said latch operators from an inoperable position remote from said first magnet to an operable position wherein a pole of said second magnet is adjacent a like pole of said first magnet where the repulsive force of the magnetic field existing between the magnets overcomes the force of the spring which biases the bolt and retracts the bolt; and inside and outside locking means selectively operable to block movement of said latch operators.

References Cited in the file of this patent UNITED STATES PATENTS 928,483 Wakeman July 20, 1909 2,205,712 Bitgood June 25, 1940 2,468,969 Galey May 3, 1949 2,809,062 Mainhardt Oct. 8, 1957 FOREIGN PATENTS 329,464 France May 30, 1903 

